The slain lawyer Bilal Kasi was President of Balochistan Bar Association who got killed when some unknown gunmen opened fire on his vehicle when he was on his way to office at Manno Jan area of Quetta.
The gunmen fled the scene after the attack.
Rahmat Baloch, provincial health minister said that the death toll is feared to rise as 20 among the injured people are said to be in critical condition.
He said that the emergency ward of the civil hospital was completely destroyed in the blast.
Baloch said that some of the injured have been shifted to Bolan Hospital and military hospital of the city as the Civil Hospital ran out of beds and other services to accommodate the blast victims.
He said that a state of emergency has been declared in all hospitals of the city to ensure the best possible medical treatment to the injured people.
No group has claimed responsibility for the attack yet.
A heavy contingent of police and paramilitary troops rushed to the site and cordoned it off for investigations.
Pakistani Prime Minister Nawaz Sharif condemned the blast and vowed to root out militancy from the country.
Following the attack, the lawyers in the province boycotted court procedures.
The explosion caused a chain reaction from the circles of lawyers from the country.
Lawyers in Balochistan and the country's southern port city of Karachi boycotted court proceedings.
The Pakistan Bar Association condemned the attack and announced a three-day mourning.